Windows: Support direct password drag-n-drop from external applications (e.g. KeePass) which is more secure than using clipboard.

src/Common/Dlgcode.c

@@ -11638,6 +11638,17 @@ BOOL CALLBACK SecurityTokenPasswordDlgProc (HWND hwndDlg, UINT msg, WPARAM wPara
 
 			SetForegroundWindow (hwndDlg);
 			SetFocus (GetDlgItem (hwndDlg, IDC_TOKEN_PASSWORD));
+
+			if (!bSecureDesktopOngoing)
+			{
+				PasswordEditDropTarget* pTarget = new PasswordEditDropTarget ();
+				if (pTarget->Register (hwndDlg))
+				{
+					SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) pTarget);
+				}
+				else
+					delete pTarget;
+			}
 		}
 		return 0;
 
@@ -11673,6 +11684,19 @@ BOOL CALLBACK SecurityTokenPasswordDlgProc (HWND hwndDlg, UINT msg, WPARAM wPara
 			EndDialog (hwndDlg, lw);
 		}
 		return 1;
+
+	case WM_NCDESTROY:
+		{
+			/* unregister drap-n-drop support */
+			PasswordEditDropTarget* pTarget = (PasswordEditDropTarget*) GetWindowLongPtr (hwndDlg, DWLP_USER);
+			if (pTarget)
+			{
+				SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) 0);
+				pTarget->Revoke ();
+				pTarget->Release();
+			}
+		}
+		return 0;
 	}
 
 	return 0;
@@ -14474,3 +14498,401 @@ BitLockerEncryptionStatus GetBitLockerEncryptionStatus(WCHAR driveLetter)
     CoUninitialize();
     return blStatus;
 }
+
+////////////////////////////////////////////////////////////////////////////////////////
+
+static CLIPFORMAT g_supportedFormats[] = { CF_UNICODETEXT, CF_TEXT, CF_OEMTEXT};
+
+//*************************************************************
+//	GenericDropTarget
+//*************************************************************
+GenericDropTarget::GenericDropTarget(CLIPFORMAT* pFormats, size_t count)
+	:	m_DropTargetWnd(NULL),
+		m_dwRefCount(1),
+		m_KeyState(0L),
+		m_Data(NULL)
+{
+	m_DropPoint.x = 0;
+	m_DropPoint.y = 0;
+
+	if (pFormats && count)
+	{
+		for (size_t i = 0; i < count; i++)
+		{
+			m_SupportedFormat.push_back (pFormats[i]);
+		}
+	}
+}
+
+GenericDropTarget::~GenericDropTarget()
+{
+}
+
+HRESULT GenericDropTarget::QueryInterface(REFIID iid, void **ppvObject)
+{
+	if(ppvObject == NULL)
+		return E_FAIL;
+	
+    if (iid == IID_IUnknown)
+    {
+		AddRef();
+		(*ppvObject) = this;
+		return S_OK;
+    }
+	//	compare guids fast and dirty
+    if (IsEqualGUID (iid, IID_IDropTarget))
+	{
+		AddRef();
+		(*ppvObject) = this;
+		return S_OK;
+	}
+
+	return E_FAIL;
+}
+
+ULONG GenericDropTarget::AddRef(void)
+{
+	return (ULONG) InterlockedIncrement (&m_dwRefCount);
+}
+
+ULONG GenericDropTarget::Release(void)
+{
+	if (InterlockedDecrement (&m_dwRefCount) == 0)
+	{
+		delete this;
+		return 0;
+	}
+	else
+		return (ULONG) m_dwRefCount;
+}
+
+//*************************************************************
+//	Register
+//		Called by whom implements us so we can serve
+//*************************************************************
+BOOL GenericDropTarget::Register(HWND hWnd)
+{
+	if(NULL == hWnd)
+		return E_FAIL;
+
+	OleInitialize(NULL);
+
+	//	required: these MUST be strong locked
+	CoLockObjectExternal(this, TRUE, 0);
+
+	//	this is ok, we have it
+	DWORD hRes = ::RegisterDragDrop(hWnd, this);
+	if(SUCCEEDED(hRes))
+	{
+		//	keep
+		m_DropTargetWnd = hWnd;
+		return TRUE;
+	}
+
+	//	unlock
+	CoLockObjectExternal(this, FALSE, 0);
+
+	// bye bye COM
+	OleUninitialize();
+
+	//	wont accept data now
+	return FALSE;
+}
+
+//*************************************************************
+//	Revoke
+//		Unregister us as a target
+//*************************************************************
+void GenericDropTarget::Revoke()
+{
+	if(NULL == m_DropTargetWnd)
+		return;
+
+	RevokeDragDrop(m_DropTargetWnd);
+
+	m_DropTargetWnd = NULL;
+
+	//	unlock
+	CoLockObjectExternal(this, FALSE, 0);
+
+	// bye bye COM
+	OleUninitialize();
+}
+ 
+//*************************************************************
+//	DragEnter
+//*************************************************************
+HRESULT	GenericDropTarget::DragEnter(struct IDataObject *pDataObject, unsigned long grfKeyState, struct _POINTL pMouse, unsigned long * pDropEffect)
+{
+	if(pDataObject == NULL)
+		return E_FAIL;	//	must have data
+
+	//	keep point
+	m_DropPoint.x = pMouse.x;
+	m_DropPoint.y = pMouse.y;
+
+	//	keep key
+	m_KeyState = grfKeyState;
+
+	//	call top
+	*pDropEffect = GotEnter();
+
+	return S_OK;
+}
+
+//*************************************************************
+//	DragOver
+//		Coming over!
+//*************************************************************
+HRESULT	GenericDropTarget::DragOver(unsigned long grfKeyState, struct _POINTL pMouse, unsigned long *pEffect)
+{
+	//	keep point
+	m_DropPoint.x = pMouse.x;
+	m_DropPoint.y = pMouse.y;
+
+	//	keep key
+	m_KeyState = grfKeyState;
+
+	//	call top
+	*pEffect = GotDrag();
+
+	return S_OK;
+}
+
+//*************************************************************
+//	DragLeave
+//		Free! At last!
+//*************************************************************
+HRESULT	GenericDropTarget::DragLeave(void)
+{
+	GotLeave();
+
+	return S_OK;
+}
+
+//*************************************************************
+//	Drop
+//*************************************************************
+HRESULT	GenericDropTarget::Drop(struct IDataObject *pDataObject, unsigned long grfKeyState, struct _POINTL pMouse, unsigned long *pdwEffect)
+{
+	if(NULL == pDataObject)
+		return E_FAIL;
+
+	//	do final effect
+	*pdwEffect = DROPEFFECT_COPY;
+	
+	//	Check the data
+	FORMATETC iFormat;
+	ZeroMemory(&iFormat, sizeof(FORMATETC));
+
+	STGMEDIUM iMedium;
+	ZeroMemory(&iMedium, sizeof(STGMEDIUM));
+
+	HRESULT hRes;
+	size_t i;
+	bool bFound = false;
+
+	for (i = 0; i < m_SupportedFormat.size(); i++)
+	{
+		//	data
+		iFormat.cfFormat = m_SupportedFormat[i];	
+		iFormat.dwAspect = DVASPECT_CONTENT;
+		iFormat.lindex = -1;			//	give me all baby
+		iFormat.tymed = TYMED_HGLOBAL;	//	want mem
+
+		hRes = pDataObject->GetData(&iFormat, &iMedium);
+		if(SUCCEEDED(hRes))
+		{
+			bFound = true;
+			break;
+		}
+	}
+
+	if (!bFound)
+		return hRes;
+
+	//	we have the data, get it		
+	BYTE *iMem = (BYTE *)::GlobalLock(iMedium.hGlobal);
+
+	//	pass over
+	m_Data = iMem;
+	
+	//	keep point
+	m_DropPoint.x = pMouse.x;
+	m_DropPoint.y = pMouse.y;
+
+	//	keep key
+	m_KeyState = grfKeyState;
+
+	//	notify parent of drop
+	GotDrop(m_SupportedFormat[i]);
+
+	::GlobalUnlock(iMedium.hGlobal);
+
+	//	free data
+	if(iMedium.pUnkForRelease != NULL)
+		iMedium.pUnkForRelease->Release();
+
+	return S_OK;
+}
+
+//*************************************************************
+//	Stub implementation
+//		Real stuff would be done in parent
+//*************************************************************
+void GenericDropTarget::GotDrop(CLIPFORMAT format)
+{
+}
+
+DWORD GenericDropTarget::GotDrag(void)
+{
+	return DROPEFFECT_LINK;
+}
+
+void GenericDropTarget::GotLeave(void)
+{
+}
+
+DWORD GenericDropTarget::GotEnter(void)
+{
+	return DROPEFFECT_LINK;
+}
+
+// ************************************************************
+//	PasswordEditDropTarget
+//		Constructor
+// ************************************************************
+PasswordEditDropTarget::PasswordEditDropTarget() : GenericDropTarget (g_supportedFormats, ARRAYSIZE (g_supportedFormats))
+{
+
+}
+
+// ************************************************************
+//	GotDrag
+
+// ************************************************************
+DWORD PasswordEditDropTarget::GotDrag(void)
+{
+	return GotEnter();  
+}
+
+// ************************************************************
+//	GotLeave
+// ************************************************************
+void PasswordEditDropTarget::GotLeave(void)
+{
+}
+
+// ************************************************************
+//	GotEnter
+// ************************************************************
+DWORD PasswordEditDropTarget::GotEnter(void)
+{
+	TCHAR szClassName[64];
+	DWORD dwStyles;
+	int maxLen;
+	HWND hChild = WindowFromPoint (m_DropPoint);
+	// check that we are on password edit control (we use maximum length to correctly identify password fields since they don't always have ES_PASSWORD style (if the the user checked show password)
+	if (hChild && GetClassName (hChild, szClassName, ARRAYSIZE (szClassName)) && (0 == _tcsicmp (szClassName, _T("EDIT")))
+		&& (dwStyles = GetWindowLong (hChild, GWL_STYLE)) && !(dwStyles & ES_NUMBER)
+		&& (maxLen = (int) SendMessage (hChild, EM_GETLIMITTEXT, 0, 0)) && (maxLen == MAX_PASSWORD || maxLen == MAX_LEGACY_PASSWORD)
+		)
+	{
+		return DROPEFFECT_COPY; 
+	}
+
+	return DROPEFFECT_LINK;
+}
+
+// ************************************************************
+//	GotDrop
+//		Called if we have a drop text drop here.
+//	
+// ************************************************************
+void PasswordEditDropTarget::GotDrop(CLIPFORMAT format)
+{
+	//	value contains the material itself
+	if(m_Data)
+	{
+		TCHAR szClassName[64];
+		DWORD dwStyles;
+		int maxLen;
+		HWND hChild = WindowFromPoint (m_DropPoint);
+		if (hChild && GetClassName (hChild, szClassName, ARRAYSIZE (szClassName)) && (0 == _tcsicmp (szClassName, _T("EDIT")))
+			&& (dwStyles = GetWindowLong (hChild, GWL_STYLE)) && !(dwStyles & ES_NUMBER)
+			&& (maxLen = (int) SendMessage (hChild, EM_GETLIMITTEXT, 0, 0)) && (maxLen == MAX_PASSWORD || maxLen == MAX_LEGACY_PASSWORD)
+			)
+		{
+			WCHAR* wszText;
+			int wlen;
+			bool bFree = false;
+			//	get the text
+			if (format == CF_UNICODETEXT)
+			{
+				wszText = (WCHAR *)m_Data;			
+			}
+			else
+			{
+				char *iText = (char *)m_Data;
+				wlen = MultiByteToWideChar ((format == CF_OEMTEXT)? CP_OEMCP : CP_ACP, 0, iText, -1, NULL, 0);
+				wszText = new WCHAR[wlen];
+				if (wszText)
+				{
+					wlen = MultiByteToWideChar (CP_ACP, 0, iText, -1, wszText, wlen);
+					bFree = true;
+				}
+			}
+
+			WCHAR* pchData = wszText;
+			int txtlen = 0;
+			bool bTruncated = false;
+
+			// remove any appended \r or \n
+			while (*pchData)
+			{
+				if (*pchData == '\r' || *pchData == '\n')
+					break;
+				else
+				{
+					txtlen++;
+					pchData++;
+				}
+			}
+
+			if (txtlen)
+			{
+				if (txtlen > maxLen)
+				{
+					bTruncated = true;
+					txtlen = maxLen;
+				}
+
+				SetFocus (hChild);
+
+				wszText[txtlen] = 0;
+				SetWindowText(hChild , wszText);
+
+				if (bTruncated)
+				{
+					EDITBALLOONTIP ebt;
+
+					ebt.cbStruct = sizeof( EDITBALLOONTIP );
+					ebt.pszText = GetString ("PASSWORD_PASTED_TRUNCATED");
+					ebt.pszTitle = lpszTitle;
+					ebt.ttiIcon = TTI_WARNING_LARGE;    // tooltip warning icon
+
+					SendMessage(hChild, EM_SHOWBALLOONTIP, 0, (LPARAM)&ebt);
+
+					MessageBeep (0xFFFFFFFF);
+				}
+			}
+
+			if (bFree)
+			{
+				burn (wszText, wlen * sizeof (WCHAR));
+				delete [] wszText;
+			}
+		}
+	}
+}
+

src/Common/Dlgcode.h

@@ -691,6 +691,61 @@ typedef void (CALLBACK* WaitThreadProc)(void* pArg, HWND hWaitDlg);
 void BringToForeground(HWND hWnd);
 void ShowWaitDialog(HWND hwnd, BOOL bUseHwndAsParent, WaitThreadProc callback, void* pArg);
 
+// classes used to implement support for password drag-n-drop from KeePass Password Safe
+// Implementation based the following source code with many modifications to fix isses and add features
+// URL: https://www.codeguru.com/cpp/misc/misc/draganddrop/article.php/c349/Drag-And-Drop-between-Window-Controls.htm
+
+interface GenericDropTarget : public IDropTarget
+{
+public:
+	GenericDropTarget(CLIPFORMAT* pFormats, size_t count);
+	~GenericDropTarget();
+
+	//	basic IUnknown stuff
+	HRESULT	STDMETHODCALLTYPE	QueryInterface(REFIID iid, void ** ppvObject); 
+	ULONG	STDMETHODCALLTYPE	AddRef(void); 
+	ULONG	STDMETHODCALLTYPE	Release(void); 
+
+	HRESULT	STDMETHODCALLTYPE	DragEnter(struct IDataObject *,unsigned long,struct _POINTL,unsigned long *); 
+	HRESULT	STDMETHODCALLTYPE	DragOver(unsigned long,struct _POINTL,unsigned long *); 
+	HRESULT	STDMETHODCALLTYPE	DragLeave(void);
+	HRESULT	STDMETHODCALLTYPE	Drop(struct IDataObject *,unsigned long,struct _POINTL,unsigned long *);
+
+	//	called by parents
+	BOOL						Register(HWND hWnd);
+	void						Revoke();
+
+	//	call parent we have goodies
+	virtual	void				GotDrop(CLIPFORMAT format);
+	virtual	DWORD				GotDrag(void);
+	virtual	void				GotLeave(void);
+	virtual	DWORD				GotEnter(void);
+public:
+	BYTE			*m_Data;
+
+	POINT			m_DropPoint;
+
+	DWORD			m_KeyState;
+
+protected:
+	HWND			m_DropTargetWnd;
+	std::vector<CLIPFORMAT> m_SupportedFormat;
+	volatile LONG	m_dwRefCount;
+};
+
+class PasswordEditDropTarget : public GenericDropTarget
+{
+public:
+	PasswordEditDropTarget();
+
+	//	called by child we have drop
+	void	GotDrop(CLIPFORMAT format);
+	DWORD	GotDrag(void);
+	void	GotLeave(void);
+	DWORD	GotEnter(void);
+};
+
+
 #endif // __cplusplus
 
 #endif // TC_HEADER_DLGCODE

src/ExpandVolume/WinMain.cpp

@@ -490,6 +490,17 @@ BOOL CALLBACK ExtcvPasswordDlgProc (HWND hwndDlg, UINT msg, WPARAM wParam, LPARA
 
 				SetWindowPos (hwndDlg, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);
 			}
+
+			if (!bSecureDesktopOngoing)
+			{
+				PasswordEditDropTarget* pTarget = new PasswordEditDropTarget ();
+				if (pTarget->Register (hwndDlg))
+				{
+					SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) pTarget);
+				}
+				else
+					delete pTarget;
+			}
 		}
 		return 0;
 
@@ -782,6 +793,19 @@ BOOL CALLBACK ExtcvPasswordDlgProc (HWND hwndDlg, UINT msg, WPARAM wParam, LPARA
 			DragFinish (hdrop);
 		}
 		return 1;
+
+	case WM_NCDESTROY:
+		{
+			/* unregister drap-n-drop support */
+			PasswordEditDropTarget* pTarget = (PasswordEditDropTarget*) GetWindowLongPtr (hwndDlg, DWLP_USER);
+			if (pTarget)
+			{
+				SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) 0);
+				pTarget->Revoke ();
+				pTarget->Release();
+			}
+		}
+		return 0;
 	}
 
 	return 0;

src/Format/Tcformat.c

@@ -6372,6 +6372,14 @@ BOOL CALLBACK MainDialogProc (HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lPa
 			strcpy (szRawPassword, "q");
 #endif
 
+			PasswordEditDropTarget* pTarget = new PasswordEditDropTarget ();
+			if (pTarget->Register (hwndDlg))
+			{
+				SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) pTarget);
+			}
+			else
+				delete pTarget;
+
 			PostMessage (hwndDlg, TC_APPMSG_PERFORM_POST_WMINIT_TASKS, 0, 0);
 		}
 		return 0;
@@ -8995,6 +9003,22 @@ ovf_end:
 	case WM_CLOSE:
 		PostMessage (hwndDlg, TC_APPMSG_FORMAT_USER_QUIT, 0, 0);
 		return 1;
+
+	case WM_NCDESTROY:
+		{
+			hPasswordInputField = NULL;
+			hVerifyPasswordInputField = NULL;
+
+			/* unregister drap-n-drop support */
+			PasswordEditDropTarget* pTarget = (PasswordEditDropTarget*) GetWindowLongPtr (hwndDlg, DWLP_USER);
+			if (pTarget)
+			{
+				SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) 0);
+				pTarget->Revoke ();
+				pTarget->Release();
+			}
+		}
+		return 0;
 	}
 
 	return 0;

src/Mount/Mount.c

@@ -2416,6 +2416,17 @@ BOOL CALLBACK PasswordChangeDlgProc (HWND hwndDlg, UINT msg, WPARAM wParam, LPAR
 
 			CheckCapsLock (hwndDlg, FALSE);
 			
+			if (!bSecureDesktopOngoing)
+			{
+				PasswordEditDropTarget* pTarget = new PasswordEditDropTarget ();
+				if (pTarget->Register (hwndDlg))
+				{
+					SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) pTarget);
+				}
+				else
+					delete pTarget;
+			}
+
 			return 0;
 		}
 
@@ -2880,6 +2891,19 @@ err:
 			return 1;
 		}
 		return 0;
+
+	case WM_NCDESTROY:
+		{
+			/* unregister drap-n-drop support */
+			PasswordEditDropTarget* pTarget = (PasswordEditDropTarget*) GetWindowLongPtr (hwndDlg, DWLP_USER);
+			if (pTarget)
+			{
+				SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) 0);
+				pTarget->Revoke ();
+				pTarget->Release();
+			}
+		}
+		return 0;
 	}
 
 	return 0;
@@ -3014,9 +3038,18 @@ BOOL CALLBACK PasswordDlgProc (HWND hwndDlg, UINT msg, WPARAM wParam, LPARAM lPa
 			SetFocus (GetDlgItem (hwndDlg, IDC_PASSWORD));
 
 			/* Start the timer to check if we are foreground only if Secure Desktop is not used */
+			/* Implement Text drag-n-drop in order to support droping password from KeePass directly only if Secure Desktop is not used */
 			if (!bSecureDesktopOngoing)
 			{
 				SetTimer (hwndDlg, TIMER_ID_CHECK_FOREGROUND, TIMER_INTERVAL_CHECK_FOREGROUND, NULL);
+
+				PasswordEditDropTarget* pTarget = new PasswordEditDropTarget ();
+				if (pTarget->Register (hwndDlg))
+				{
+					SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) pTarget);
+				}
+				else
+					delete pTarget;
 			}
 		}
 		return 0;
@@ -3281,6 +3314,19 @@ BOOL CALLBACK PasswordDlgProc (HWND hwndDlg, UINT msg, WPARAM wParam, LPARAM lPa
 		}
 		return 0;
 
+	case WM_NCDESTROY:
+		{
+			/* unregister drap-n-drop support */
+			PasswordEditDropTarget* pTarget = (PasswordEditDropTarget*) GetWindowLongPtr (hwndDlg, DWLP_USER);
+			if (pTarget)
+			{
+				SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) 0);
+				pTarget->Revoke ();
+				pTarget->Release();
+			}
+		}
+		return 0;
+
 	case WM_CONTEXTMENU:
 		{
 			RECT buttonRect;
@@ -3694,6 +3740,17 @@ BOOL CALLBACK MountOptionsDlgProc (HWND hwndDlg, UINT msg, WPARAM wParam, LPARAM
 
 			ToHyperlink (hwndDlg, IDC_LINK_HIDVOL_PROTECTION_INFO);
 
+			if (!bSecureDesktopOngoing)
+			{
+				PasswordEditDropTarget* pTarget = new PasswordEditDropTarget ();
+				if (pTarget->Register (hwndDlg))
+				{
+					SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) pTarget);
+				}
+				else
+					delete pTarget;
+			}
+
 		}
 		return 0;
 
@@ -3851,6 +3908,19 @@ BOOL CALLBACK MountOptionsDlgProc (HWND hwndDlg, UINT msg, WPARAM wParam, LPARAM
 		}
 
 		return 0;
+
+	case WM_NCDESTROY:
+		{
+			/* unregister drap-n-drop support */
+			PasswordEditDropTarget* pTarget = (PasswordEditDropTarget*) GetWindowLongPtr (hwndDlg, DWLP_USER);
+			if (pTarget)
+			{
+				SetWindowLongPtr (hwndDlg, DWLP_USER, (LONG_PTR) 0);
+				pTarget->Revoke ();
+				pTarget->Release();
+			}
+		}
+		return 0;
 	}
 
 	return 0;